Selection Combining in Hybrid RF/FSO Systems for IM/DD and Heterodyne Detection in Varying Weather Conditions

摘要

A hybrid RF/FSO scheme that can be deployed to effectively combat the issue of signal fading in pure FSO systems is proposed in this paper. The scheme transmits the same information through the channel at the same data rate, across both RF and FSO links. At the receiver, selection combining scheme is deployed to couple the incoming signals from multiple RF receivers and a single FSO receiver. Taking into consideration the atmospheric path loss and turbulence, the closed loop expression for the Cumulative Distribution Function (CDF) is proposed. Additionally, the closed-form expressions for important performance parameters, such as Outage Probability (OP) and Bit Error Rate (BER) are also formulated, all in terms of Meijer's G function for both the Intensity Modulation/Direct Detection (IM/DD) and Heterodyne Detection techniques.